Many types of electrical current sensors are known and are in wide use today throughout the electronics industry. Commonly, many of these sensors include a Hall effect generator that senses the magnetic field associated with an electrical current and, in turn, produces a Hall effect output voltage that is proportional to the magnetic field.
Hall effect generators generally comprise a layer of homogeneous semiconductor material, known as the Hall plate, constructed upon a dielectric substrate. An excitation current is applied to the Hall plate, when the Hall effect generator is placed in a magnetic field and supplied with excitation current, the Hall effect output voltage is produced in the Hall plate which is orthogonal to the magnetic field and the excitation current, and then the output voltage is measured out.
Various types of sensing device utilizing the Hall effect phenomena have been used in the past, as disclosed in U.S. Pat. No. 5,416,407. As shown in FIG. 1, the electrical current sensor 100 comprises an amplifier 102, a constant current source 104, a gapped toroid core (not shown) mounted on the component side of a printed circuit board (PCB) (not shown), a Hall effect generator 106 extending via its output leads from the PCB into the gap of the toroid core, and an inductive loop 108 positioned at the edge of the gap of the toroid core. Concretely, the Hall effect generator 106 comprises a standard design having a semiconductor Hall plate (not shown) mounted onto a dielectric substrate (not shown) within a sealed package with its constant current leads 112 and the Hall effect output voltage leads 114 extending therefrom.
During operation, an electrical conductor is inserted through a hole in the PCB. As electrical current flows through the conductor, a magnetic field is created within the toroid core and across the gap of the toroid core. The Hall effect generator 106 and the inductive loop 108 are therefore subjected to the magnetic field. The constant current source 104 supplies a temperature-compensated constant current to the Hall plate. As a result, the Hall effect generator 106 produces an output voltage that is proportional to the magnetic field concentrated onto its Hall plate, and this output voltage is then supplied to the amplifier 102 to be amplified to a useful level, finally an electrical current can be detected.
However, the signal of the output voltage of the above-mentioned electrical current sensor 100 is lower, and the measurement accuracy is poor. Moreover, the sensitivity of the Hall element in the Hall effect generator 106 is insufficient due to the alternating and transient current.
Thus, there is a need for an improved electrical current sensor device to overcome the above drawbacks.